use a context for cancelation

README.md

@@ -2,7 +2,7 @@
 
 [![GoDoc](https://godoc.org/github.com/jbardin/readchan?status.svg)](https://godoc.org/github.com/jbardin/readchan)
 
-Package readchan provides methods for interating over an `io.Reader` by block
+Package readchan provides methods for iterating over an `io.Reader` by block
 or line, and reading the results via a channel.
 
 
@@ -11,7 +11,7 @@ or line, and reading the results via a channel.
       log.Fatal(err)
     }
 
-    for line := range readchan.Lines(f, 1, nil) {
+    for line := range readchan.Lines(context.TODO(), f, 1) {
       if line.Err != nil {
         log.Fatal(err)
       }

readchan.go

@@ -4,6 +4,7 @@ package readchan
 
 import (
 	"bufio"
+	"context"
 	"io"
 	"sync"
 )
@@ -31,9 +32,9 @@ func (c *Chunk) Done() {
 //
 // The maxSize argument sets the allocated capacity of each []byte. Reads will
 // buffer readAhead number of Chunks in the channel as soon as they are
-// available.  Closing the cancel channel will cause Reads loop to return, but
+// available.  Canceling the context will cause the Reads loop to return, but
 // it cannot interrupt pending Read calls on r.
-func Reads(r io.Reader, maxSize, readAhead int, cancel chan bool) <-chan *Chunk {
+func Reads(ctx context.Context, r io.Reader, maxSize, readAhead int) <-chan *Chunk {
 	if maxSize <= 0 {
 		panic("invalid max buffer size")
 	}
@@ -69,7 +70,7 @@ func Reads(r io.Reader, maxSize, readAhead int, cancel chan bool) <-chan *Chunk
 
 			select {
 			case readChan <- chunk:
-			case <-cancel:
+			case <-ctx.Done():
 				return
 			}
 
@@ -87,10 +88,10 @@ func Reads(r io.Reader, maxSize, readAhead int, cancel chan bool) <-chan *Chunk
 // characters.
 //
 // The readAhead argument determines the buffer size for the channel, which
-// will be filled as soon as data available. Closing the cancel channel will
+// will be filled as soon as data available. Canceling the context will
 // cause the Lines scanner loop to return, but it cannot interrupt pending Read
 // calls on r.
-func Lines(r io.Reader, readAhead int, cancel chan bool) <-chan *Chunk {
+func Lines(ctx context.Context, r io.Reader, readAhead int) <-chan *Chunk {
 	if readAhead < 0 {
 		readAhead = 1
 	}
@@ -119,7 +120,7 @@ func Lines(r io.Reader, readAhead int, cancel chan bool) <-chan *Chunk {
 
 			select {
 			case readChan <- chunk:
-			case <-cancel:
+			case <-ctx.Done():
 				return
 			}
 		}

readchan_test.go

@@ -3,6 +3,7 @@ package readchan
 import (
 	"bytes"
 	"compress/gzip"
+	"context"
 	"io"
 	"io/ioutil"
 	"log"
@@ -43,7 +44,7 @@ func TestChunkReader(t *testing.T) {
 
 	var newData []byte
 
-	readChan := Reads(testReader, 1024, 1, nil)
+	readChan := Reads(context.TODO(), testReader, 1024, 1)
 	for chunk := range readChan {
 		newData = append(newData, chunk.Data...)
 		chunk.Done()
@@ -64,7 +65,7 @@ func TestLineReader(t *testing.T) {
 	var newData []byte
 
 	lines := 0
-	readChan := Lines(testReader, 1, nil)
+	readChan := Lines(context.TODO(), testReader, 1)
 	for chunk := range readChan {
 		newData = append(newData, chunk.Data...)
 		newData = append(newData, '\n')
@@ -94,7 +95,7 @@ func BenchmarkChunkReader(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		newData = newData[:0]
 		testReader.Seek(0, 0)
-		readChan := Reads(testReader, 1024, 1, nil)
+		readChan := Reads(context.TODO(), testReader, 1024, 1)
 
 		for chunk := range readChan {
 			newData = append(newData, chunk.Data...)
@@ -116,7 +117,7 @@ func BenchmarkLineReader(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		newData = newData[:0]
 		testReader.Seek(0, 0)
-		readChan := Lines(testReader, 1, nil)
+		readChan := Lines(context.TODO(), testReader, 1)
 		for chunk := range readChan {
 			newData = append(newData, chunk.Data...)
 			chunk.Done()